package main
import (
	"fmt"
	"strings"
	"strconv"
	"sort"
)

func max(a,b int)int{
	if a>b{
		return a
	}
	return b
}

func getInt(s string)int{
	v:=strings.Split(s,":")
	h,_:=strconv.Atoi(v[0])
	m,_:=strconv.Atoi(v[1])
	return h*60+m
}



func countMaxActivity( timeSchedule [][]string ) int {
	v:=make([][]int,0)
	len1:=len(timeSchedule)
	for i:=0;i<len1;i++{
		t:=make([]int,0)
		t=append(t,getInt(timeSchedule[i][0]),getInt(timeSchedule[i][1]))
		v=append(v,t)
	}
	sort.Slice(v,func(i,j int)bool{
		return v[i][1]<v[j][1]
	})
	ans,end:=0,-1
	for i:=0;i<len1;i++{
		if end<=v[i][0]{
			ans++
			end=v[i][1]
		}
	}	

	return ans
}


func main(){
	v:=[][]string{
		[]string{"10:00","12:00"},
		[]string{"03:00","11:30"},
		[]string{"11:30","14:00"},
	}
	ans:=countMaxActivity(v)
	fmt.Printf("hello %v\n",ans);
}